A new year, a new lockdown. Cases of the virus are too high to do otherwise. In a world of purely rational people, the spreading behaviour we saw over the holiday would not have happened. Faced with the arrival of a vaccine, people should have been more cautious. It is now clear some were far less cautious. This is understandable, and I raise no judgement. Nine months of lockdowns of one kind or another is wearying for everyone. The decision to allow movement seems in retrospect a mistake given the number of cases but the trade-off the government was making…